Bladder, ureter & renal pelvis


Polypoid / papillary cystitis

Topic Completed: 1 May 2011

Minor changes: 23 November 2020

Copyright: 2003-2021,, Inc.

PubMed Search: Polypoid papillary cystitis

Monika Roychowdhury, M.D.
Page views in 2020: 6,573
Page views in 2021 to date: 8,204
Cite this page: Roychowdhury M. Polypoid / papillary cystitis. website. Accessed November 29th, 2021.
Definition / general
  • Nonspecific mucosal reaction secondary to chronically inflamed bladder, with grossly noted polypoid lesions (with edema) or papillary lesions
  • May overlap with bullous cystitis
  • Analogous lesions occur throughout the urothelial tract and are referred to as polypoid urethritis, polypoid ureteritis, and polypoid pyelititis when present in the urethra, ureter, and renal pelvis respectively
  • Rare, mean age 49 years, 75% male
  • Due to injury to bladder mucosa; seen commonly in patients with indwelling catheter and vesical fistula
  • Papillary cystitis is chronic phase of polypoid cystitis
Clinical features
  • Often, but not always due to bladder catheterization (Int Urol Nephrol 2002;34:293); more common/severe with frequent catheterization
  • Also associated with Beckwith-Wiedemann syndrome, radiation therapy
Case reports
  • Remove source of injury
Gross description
  • Friable, broad-based, often edematous bullous, polypoid or papillary lesions in dome or posterior bladder wall
  • Can mimic a papillary urothelial neoplasm cystoscopically
Microscopic (histologic) description
  • Low power diagnosis – must recognize reactive nature of process with inflamed background and urothelium of normal thickness (Am J Surg Pathol 2008;32:758)
  • Thin, finger - like papillae or broad based polypoid lesions with congestion and edema of lamina propria
  • Mild chronic inflammatory infiltrate
  • May have reactive epithelial atypia or reactive fibroblasts that appear bizarre
  • Covered by normal appearing or metaplastic urothelium with orderly maturation and surface umbrella cells (Am J Surg Pathol 1988;12:542)
  • Fronds with fibrosis can mimic papillary urothelial neoplasms; however, the fibrovascular cores tend to be simple, non-branching and broad-based
  • No hyperchromasia, no coarse chromatin, no abnormal mitotic figures
Differential diagnosis
  • Papillary urothelial neoplasms: At low power and cystoscopy, appears neoplastic and not inflammatory; prominent atypia present (papillary urothelial carcinoma is characterized by thin papillae lacking prominent inflammation, smaller papillae arising from larger papillae and stratified atypical epithelium lacking umbrella cells as opposed to broad based edematous papillary projections with prominent inflammation, lack of secondary smaller papillae and presence of umbrella cells in polypoid cystitis, Am J Surg Pathol 2008;32:758)
Additional references
Board review style question #1

    What is the correct diagnosis of the image?

  1. Low grade papillary urothelial carcinoma
  2. Papillary urothelial neoplasia of low malignant potential (PUNLMP)
  3. Polypoid cystitis
  4. Urothelial papilloma
Board review style answer #1
C. Polypoid cystitis. Note the broad base architecture of the polypoid structures associated with marked edema. The lining urothelium is thinned out and appears normal. Urothelial papilloma has a papillary architecture with thin fibrovascular cores and a normal appearing urothelial lining. Inflammation is usually not seen. Low grade urothelial carcinoma has complex papillary architecture with an atypical urothelial lining. PUNLMP show papillary structures with increased thickness of the urothelium, maintained cytologic polarity and minimal atypia.

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